An oven typically comprises a heated chamber or compartment used for baking, roasting, heating, drying and similar purposes. Every oven includes an interior or exterior source of heat. Most ovens are basically conduction ovens, which transfer heat to objects by thermal conduction through a heating medium that is essentially static air or gas within the oven structure. The hollow oven interior is typically vented to prevent pressure buildup.
Convection ovens provide rapid heat transfer by using moving heated air or gas streams to transfer heat to objects within the oven. In conventional convection ovens, movement of the air or gas stream is artificially induced by fans or blowers. The moving air or gas within a convection oven accelerates transfer of heat to objects encountered by it.
One essential feature in any oven is the provision of uniform heat transfer to all portions of the object being heated. This is particularly important when cooking foods, since most cooking applications require even heat distribution to the food mass to achieve consistency in the finished product. While this can be accomplished by larger, stationary ovens typically found in commercial and residential kitchens, uniform heat distribution is much more difficult to accomplish in smaller units, particularly in portable ovens. Electric ovens make possible the use of larger area heating elements. Where electricity is unavailable, a flame heat source must be used to heat the oven. The large heat requirements necessary to achieve typical baking temperatures within an oven enclosure typically leads to wide variations in temperatures throughout the oven. Since the heat source is usually at the bottom of the oven, this usually results in foods being overcooked at the bottom of a pan or, conversely, being undercooked at the top of a pan.
A very rudimentary form of portable oven in use today simply comprises an open-bottom enclosure which is placed directly over a heat source such as a portable stove. In this arrangement, the bottom surfaces of pans within the oven are directly exposed to the rather intense heat of the covered stove. Uniform cooking in such an oven is impossible.
To better distribute heat throughout such a portable oven, a horizontal heat baffle is usually located at the bottom of the oven. It is typically interposed between the flame heat source and the food being cooked. Since the air within such an oven is essentially static, all transfer of heat within the oven occurs by conduction, and substantial temperature gradients will be encountered from one position to another within the oven.
The improvement disclosed herein arose from an effort to overcome these problems by providing a highly efficient heat distributor to spread the concentrated radiant heat supplied by portable heat sources, and to utilize natural convection currents to direct the heat uniformly about the objects in the oven.